| Hi
if I have a disk that are merged into a server coming from another server containing a lvm snapshot How can I convert this foreign disk to an existing lv volume?
The documentation says I can use lvconvert-Zn -s targetvg/targetlv sourcevg/sourcelv
But I guess I have to perform some lvm metadata recreation first?
please let me know what steps are neede
Regards Tomas Sent from my iPhone On 17 Sep 2020, at 17:22, Heinz Mauelshagen <heinzm@xxxxxxxxxx> wrote:
Tomas,
the first PE starts at offset 2048 sectors of size 512 bytes by
default, i.e. the LVM MDA (metadata area)
is ~1MiB big (because the MDA starts at offset 1 page into the
device). If you plan for large numbers of LVs or expect very
scattered allocations which both grow the metadata, you may want to
create a
bigger MDA using vgcreate's option --metadatasize (also see
/etc/lvm/lvm.conf description on
metadata/pvmetadatasize).
On 9/16/20 5:50 PM, Tomas Dalebjörk wrote:
> hi
>
> I am trying to understand how big the lvm metadata is
>
> in the vgcfgbackup file, I can see extent_size = 8192 dev_size =
> 204800 pe_start = 2048 pe_count 24
>
> pe_count(24) * extent_size(8192) = 196608 bytes usable space of the
> total dev_size(204800) metadata size? = dev_size(204800) - 196608 =
> 8192
>
> but... pe_start is 2048? so what is pe_start here? cant be
> sectors(512)? bytes? well than ther be not aligned
>
> so where starts the actual data? and where ends the lvm metadata?
At offset 2048 sectors (1MiB into the device) / MDA ends at
sector 2047.
Mind that lvm2 metadata is text formatted (see
/etc/lvm/backup/$VGName for one)
and thus varies in size (the MDA is used as a ring buffer for 2
copies of the MDA to
support atomic updates). As pointed out above when refering to
'vgcreate --metadatasize',
in more elaborate setups you may run out of MDA space.
Heinz
>
> regards Tomas Sent from my iPhone
>
>
> _______________________________________________ linux-lvm mailing
> list linux-lvm@xxxxxxxxxx
> https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO
> at http://tldp.org/HOWTO/LVM-HOWTO/
|
_______________________________________________
linux-lvm mailing list
linux-lvm@xxxxxxxxxx
https://listman.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
